This invention relates to devices for applying compression to parts of the body for therapeutic reasons.
Compression applied to a body part, such as a limb, is essential for resolving many circulatory disorders. The application of compression at the appropriate level has therapeutic benefits. For example, it restores circulation, relieves swelling, treats pain, heals ulcers, and treats varicose veins.
Elastic and inelastic garments have been employed in compression therapy of the limbs. Most of these garments suffer various degrees of shortcomings, particularly discomfort, loss of compression, difficulties in application and removal, lack of adjustability, and ineffectiveness.
A desirable trait of compression devices is that they provide to the limb compression levels that are dynamic, fluctuating in response to short-term changes inside the body part. Compression requirements change as internal pressures change, depending on whether the patient is upright or prone. Furthermore, the movement of fluid out of a body part is facilitated by the pumping effect caused by fluctuations in pressures. Such pressure fluctuations can be enhanced by compression devices that resist changes in limb size, such as those that occur during muscle flexion.
Patients have observed that stockings, wraps, and bandaging systems made entirely of elastic materials are uncomfortable. Fully elastic devices deliver an unchanging level of pressure, which alternately feels either “too tight” or “too loose” to the patient depending on the patient's position. These elastic systems also do not resist small changes in limb circumference, and hence do not provide the fluctuating pressures that are needed to assist with pumping fluid out of the body part.
To be effective, compression devices need to maintain appropriate compression over time. Large changes can occur in limb volume, reflecting either diurnal fluctuations or progressive changes in the degree of swelling. Devices that provide compression through the wrapping of materials with limited elasticity, such as with the Unna's boot, cannot accommodate such changes in limb volume. For example, they may initially provide appropriate compression, which is dynamic in response to internal changes, but after hours of use the movement of fluid out of the limb will result in an overall loss of pressure. And because these systems are wrapped around the limb in layers, it is not practical to periodically remove and re-apply the wrapping at the appropriate compression level.
In the case of more elastic systems, such as long-stretch bandages and elastic stockings, the greater elasticity helps them to sustain consistent compression levels over time. However, if changes in limb volume are great enough, pressures under the devices can go outside the appropriate therapeutic range. An additional problem with elastic stockings is that if they are sized incorrectly, or if the body part is of an irregular shape, the pressure could be incorrect under all or part of the garment from the onset. In the case of elastic bandages, it is easy to apply the layers at too high or low of a pressure, requiring a time-consuming removal and re-application.
A useful trait of compression garments is that they be easy to apply and adjust. This helps to ensure appropriate, sustained compression levels by allowing the user to adjust to accommodate changes in limb volume, and enabling the garment to be adjusted to an exact fit regardless of limb shape. Being easy to apply also increases the likelihood that the patient will continue to use the device and obtain its therapeutic benefits. Stockings can not be adjusted and are difficult to slide onto the limb. Bandaging systems can not be adjusted without being removed completely, and require skill for proper application.
Devices such as described in U.S. Pat. No. 5,653,244 are primarily inelastic, and can be adjusted through series of interlocking bands. As such they provide dynamic compression that can be sustained over time. However, because they are primarily inelastic, compression levels quickly go down with changes in volume, so sustaining compression requires frequent re-adjustment of the bands. Another consequence of being primarily inelastic is that it is more difficult to hold force in the bands while applying, and as a consequence, more effort is required by the user during application—either in the form of greater force, or the use of a greater number of bands on the garment. Furthermore, because the pairs of bands interlock—one member of a pair of bands passes through a hole in the other member—they require a certain amount of manual dexterity to apply. This is particularly disadvantageous, as many users are older or have other limitations of mobility.
Compression devices are therefore needed that are easy to apply, and that provide compression that is both sustained (in that significant long-term changes in limb volume can be accommodated), and dynamic (such that short-term changes to internal pressure can be countered). To this end, compression devices are needed that provide the ability to apply and adjust compression as quickly and easily as possible. Compression devices are also needed that are inelastic enough to provide compression levels that respond dynamically to changes in patients' compression requirements, while still being elastic enough so that the device does not readily loose appropriate compression. A need also exists for compression devices that can be applied to parts of the body that have varying circumference and that are comfortable to wear throughout the day and in different postures.
Sustained yet dynamic compression is key to proper treatment. It is often a problem with compression devices that the applied compression goes down over time or with changes in limb volume. It is often a problem with other devices that in order to sustain compression, the device must be so elastic that compression levels do not fluctuate with changes in patient need. Providing compression that has a low but significant level of elasticity, and having a means of easily adjusting compression levels, enables sustained and dynamic compression levels to be maintained.
U.S. Pat. No. 3,845,769 relates to a boot having a split sleeve of essentially unyielding material shaped to fit a leg. The sleeve is held in position and compression is applied by a plurality of bands of interlocking fabric material, such as Velcro or Scotchmate.
U.S. Pat. No. 4,215,687 relates to a combination or kit, which permits the in situ construction and assembly of a therapeutic compression device directly on the patient by a doctor or other skilled person. The combination or kit includes a Velcro-type anchoring tape having an interlocking fabric material on one side and a plurality of body or limb encircling Velcro-type bands which are assembled, one by one, in edge-to-edge relationship either by direct contact with the anchoring tape or by indirect contact through Velcro-type splicing means. These custom-made therapeutic compression devices have achieved wide recognition in healing leg ulcers and in the treatment of lymph edema. On the other hand, the custom construction which requires splicing of the body or limb encircling bands when they are too long and when the portion of the body or limb is contoured is a tedious and time consuming task.
U.S. Pat. No. 5,120,300 relates to a compression band for use in the therapeutic device disclosed in U.S. Pat. No. 4,215,687 and, more particularly, to a compression band for quick and easy application to and removal from a body part.
U.S. Pat. No. 5,254,122 relates to a therapeutic compression device of the type disclosed in U.S. Pat. No. 4,215,687 which includes a longitudinally extending splicing band or slide fastener which facilitates quick and easy removal of the device from the body or limb and quick and easy reapplication to the body or limb without the necessity of unthreading the adjusted compression bands.
U.S. Pat. No. 5,653,244 relates to a therapeutic compression garment made of flexible, foldable, light weight Velcro-type loop fabric having a central region for wrapping partially around a body part and a plurality of pairs of bands integrally connected to the central region and extending outwardly in opposite directions from both sides of the central region to encompass the body part. One of the bands of each pair has a slot to accommodate the opposite band in threaded, folded relationship.
U.S. Pat. Nos. 5,918,602 and 5,906,206 relate to the therapeutic garment disclosed in U.S. Pat. No. 5,653,244 and adapted for the leg in combination with an ankle-foot wrap for applying therapeutic compression to the leg, ankle and foot.
U.S. Pat. No. 6,338,723 relates to a device for compression of objects such as parts of the body. The device has the form of a band sized to encircle the compressible object and having a component or components made of an elastic material. Indicia are printed on the device such that the stretch of the elastic material as the device is tensioned around the body part causes increased separation of the indicia or movement of a free end of the band with respect to the indicia. A system measures the separation of the indicia and converts it to compression as a function of the circumference of the body part.